Electrical portable hedge trimmer



y 1950 W. W. HALL $2,309,564-

ELECTRICAL PORTABLE HEDGE TRIMMER Filed Oct. 5, 1.946 2 SheetsSheet l Bummer ay 30, EU W. MALL ELECTRICAL PDRTABLE HEDGE TRIMMER 2 Sheets-$heet 2 Filed on. 5, 1,946

ISnvenior attorney Patented May 30, 1950 UNH'ED STATES PATENT OFFICE ELECTRICAL PORTABLE HEDGE TRIMMER William R. Hall, New York, N Y.

Application October 5, 1946, Serial No. 701,553

3 Claims. 1

This invention relates to an improved hedge trimmer and one of its objects is to provide a device which may be carried by the operator and controlled by two handles, but operated by an electrical motor and mechanism arranged to move a sliding cutter blade against another cutter blade.

A further object of the invention is to provide a device of this character with means for simultaneously operating two complementary cutter blades toward each other and away from each other from a single electrical motor.

With the above and other objects in view the invention comprises certain new and useful con structions, combinations and arrangements of parts, clearly described in the following specificcation, and fully illustrated in the drawings, in which- Fig. 1 is a top plan view, with a gear partly exposed by breaking away a side shielding part.

Fig. 2 is an end elevation thereof.

Fig. 3 is a detail plan view, showing the mechanism for shifting the movable cutter blade.

Fig. 4 is a transverse sectional View, taken on line 4-4 of Fig. 3, looking in the direction of the arrows.

Fig. 5 is a fragmentary plan view of a mechanism for shifting both cutter blades.

Fig. 6 is a fragmentary plan view showing the position of the eccentric and the slot in which it operates.

Fig. 7 is a similar view showing another position of the eccentric pin.

Fig. 8 is a similar view, showing a third position of the eccentric pin.

Fig. 9 is a transverse sectional view showing the upper and lower cutter blades and a single disc with separate eccentric pins for operating the two blades to produce a shearing motion of one blade against the other.

Referring to the drawings, which illustrate the practical embodiment of the invention, 5 designates a frame plate on which the left handle 6 is mounted on one side of the center of the plate, and on which the right handle I on the other side of the center of the plate. The right handle 1 is provided with an electrical switch ll, and conductor wires are extended through this handle to the switch.

Between the two handles, which diverge from each other an electrical motor 9 is supported. This motor is provided with an armature shaft equipped with a gear worm ID, which engages the gear worm wheel II, which turns on the vertical shaft l2, secured to the frame plate 5.

The frame plate 5 is equipped with stationary cutter blade l3, which is provided with a series of cutter teeth l4, spaced from each other to provide openings to receive twigs and parts of plants to be cut, and each of these teeth is formed with bevelled side cutting edges. The blade I3 is secured in place on the frame plate 5 by means of the bolts l5.

A movable cutter blade I6 is provided with openings or slots ll, Ill and I9, which are disposed in parallel relation to the forward edge of the plate, and through these slots the shanks of the bolts l5 extend. Each bolt is provided with a large head Lie to prevent lateral displacement of the blade. The blade I6 is formed with cutting teeth 20, similar in design to the cutting teeth M of the stationary blade Hi.

The movable cutter blade I5 is formed with a central operating arm 2|, which is provided with a longitudinal slot 22, and the shaft I2 of the worm gear wheel extends through this slot. This shaft is also equipped with a circular disc 23, which is provided with an eccentric pin 24, having a large head 24a, and the shank of this 26 pin extends through the slot 22 of the operating arm 2|. The slots ll, l8 and i9 permit of limited horizontal motion in both directions of the cutter blade l6, and the rotary motion of the eccentric pin 24 is converted to an oscillating motion by the action of the eccentric pin in the slot 22 of the operating arm, so that the movable blade is actuated first in one direction and then in the opposite direction across the teeth i i of the fixed cutter blade. Due to the gear reduction obtained by the gear worm and worm wheel the reciprocating motion of the movable cutter blade will be considerably slower than the corresponding speed of the motor shaft.

Referring now to Figs. 5 to 9, inclusive, 3n dosignates a frame plate, which forms a bearing for disc 3|, which is rotated by means of the shaft 32 of the worm gear, not shown, but which is similar to that shown in Fig. 1.

On the frame plate 3|) an upper cutter blade 33 is slidable, and for this purpose is provided with longitudinal slots 34, through which connecting bolts 35 extend. A lower cutter blade 35 is also mounted on the frame plate 3|], and is provided with corresponding longitudinal slots 31, The blades are coupled for relative sliding motion by the connecting bolts 35, which extend through the slots 34 and the slots 37.

The cutter blade 33 is formed with an operating arm it, which has a slot 39 of cruciform shape, thus providing a main portion 39a. which is disposed at right angles to the blade 33, and another or minor portion 3% which is disposed in parallel relation to the length of the blade.

The cutter blade 36 is formed with a similar operating arm at, which [is also provided with a cruciform slot lll. These blades 33 and 35 are shifted in opposite directions to cross each other to produce a shear cutting action, by means of the circular disc (ll, carried by the shaft 32 of the worm gear wheel. This disc i provided with an eccentric pin 42 to engage the slot 3d of the cutter blade 33, and with an eccentric pin 43 to engage the slot 41 of the cutter blade 35.

When the shaft 32 rotates the disc will cause the two blades 33 and 36 to slide toward and away from each other, so that the V-shaped cutting teeth thereof will slide on each other to shear cut any twigs or parts of plants disposed between the teeth of the two blades. The eccentric pins operate in the portions of the slots which are disposed at right angles to the length of the blades, and the cross slots provide means for avoiding the binding of the shaft 32 against either or both blades.

The entire device can only be operated when both handles are grasped by the user. This compels the user to use both hands and arms to guide the cutting action, and it is impossible for the user to get his or her fingers in the path of the teeth of the cutting blades While both hands are engaged in grasping the two handles.

Various changes in the details of construction, their combination and arrangement, may be made in carrying out the invention, as defined in the claims herein set forth.

Having described the invention, 1 claim as new:

1. An electrical portable hedge trimmer, comprising a frame plate having a handle attached thereto, upper and lower cutter blades overlying one another and connected to the plate for sliding motion over one another, a rotatable member journalled in the plate for rotation, said rotatable member having pins extending fro-m the opposite sides of the member and at diametrically opposite locations thereon, said member being disposed between the cutting blades and rotatable therein, each of said cutter blades having rearwardly extending operating arms with slots therein running at right angles to the blade, said slots receiving the pin extensions from the plate disposed between the respective blades, and a power device for operating the rotatable member.

2. An electrical portable hedge trimmer, comprising a frame plate having a handle attached thereto, upper and lower cutter blades overlying one another and connected to the plate for sliding motion over one another, a rotatable member journalled in the plate for rotation, said rotatable member having pins extending from the opposite sides of the member and at diametrically opposite locations thereon, said member being disposed between the cutting blades and rotatable therein, each of said cutter blades having rearwardly extending operating arms with slots therein run ning at right angles to the blade, said slots receiving the pin extensions from the plate disposed between the respective blades, and a power device for operating the rotatable member, and one of the cutter blades being recessed and vertically offset to receive the rotary driving member.

3. A portable hedge trimmer comprising a frame plate, upper and lower cutting blades overlying one another and connected to the frame plate for sliding motion relative to one another and relative to the plate, each of said cutter blades having a rearwardly extending portion with a cruciform slot therein, the lot having sections extending at right angles to the blade and parallel to the blade, a rotary member rotatably connected to the frame plate and having pin projections extending respectively into the slots of the cutter blade portions, a power device for driving the rotary member, the provision of cross portions to eliminate binding of the rotary member against either of the blades and to prevent its locking action therewith.

WILLIAM R. HALL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,489,658 Campbell Apr. 8, 1924 1,806,116 Peterson May 19, 1931 1,919,516 Koch July 25, 1933 

